Toxicological assessments rely on low-throughput, costly animal studies that deliver minimal insights into compound toxicity mechanisms. Induced pluripotent stem cells (iPSCs) are positioned to transform the evaluation of toxic compounds by enabling predictive, physiologically relevant model systems compatible with high throughput screening. Combining these iPSC benefits with high-content screening approaches that enable diverse mechanistic and phenotypic readouts in living cells will deliver important new predictive toxicity evaluation capabilities. The goal of this contract is to demonstrate the feasibility and benefits of this approach by delivering a novel multiplexed 384-well plate format high-content assay with 2 distinct mechanistic stress-response readouts and 2 phenotypic organelle-based reporters in iPSC-derived cardiomyocytes. Cairn will validate the assays response to tool compounds known to cause cardiotoxicity and demonstrate its compatibility with high-throughput screening of at least 10,000 samples/day.